1. Field of the Invention
This invention relates to a driving mechanism for motor vehicles having at least two live axles, which driving mechanism comprises an engine having a shaft which extends transversely to the direction of travel, a change-speed transmission having shafts which are parallel to the engine shaft and adapted to drive one live axle via a spur gear train, and as means for driving the other live axle a first angle drive, which is operatively connected to the spur gear train, a second angle drive operatively connected to the second live axle, and a universal-joint shaft inter-connected between said first and second angle drives.
2. Description of the Prior Art
British Patent Specification No. 887,849 describes a driving mechanism of that kind, in which the distance from the axis of the driven gear of the spur gear train and the driving bevel gear of the first angle drive to the gear-box of the spur gear change-speed transmission is relatively large so that the driving bevel gear of the first angle drive has a large radius and the driving pinion of the second angle drive is relatively small. This is due to the fact that the transmission ratio determined by the driving gear of the first angle drive and its driven gear must be inverse to the transmission ratio determined by the driving pinion and the driven gear of the second angle drive so that the two live axles will rotate at the same speed. For design reasons it it not always possible to provide the axis of the driven gear of the spur gear train and the driving bevel gear of the first angle drive at a large distance from the housing of the change-speed transmission and in such case the driving bevel gear of the first angle drive must be relatively small in diameter so that the diameter of the driving bevel gear of the second angle drive must be increased although this is not desirable because it is desired to provide the second angle gear with a pinion which is relatively small in diameter.